An inkjet recording apparatus is widespread, which is configured to supply ink from an ink cartridge to an inkjet recording head and eject an ink droplet from the recording head onto a recording medium, to thereby produce a record of, for example, an image or a character.
Such an inkjet recording head is widely adopted not only for a small-format recording head used in a home, a small office, or the like, but also for a large-format recording head that can perform printing onto a large recording medium having a width of more than 1 m.
In such an inkjet recording apparatus, an inkjet recording head is mounted on a carriage configured to reciprocate over a recording medium in a width direction thereof, and ink is ejected onto the recording medium on a go path and on a return path. A position of the carriage is obtained by reading a linear scale arranged along a direction of movement of the carriage by a sensor mounted on the carriage. In general, a device referred to as a linear encoder is used.
Ink is ejected on a go path and on a return path based on the position of the carriage, but the positions of the carriage and the recording head mounted on the carriage subtly deviate from target positions due to an error at the time of installation, a difference in thickness of the recording medium used, or the like. Therefore, it is necessary to correct the deviation. A test pattern is printed on a recording medium, an amount of deviation is determined from the test pattern, and a correction value corresponding to the amount of deviation is input to the recording apparatus. Based on the input correction, the position at which ink is to be ejected is changed to eliminate the deviation.
Further, for example, in Patent Application Publication NO. JP 2012-153021 A, there is disclosed a technology of recording such a test pattern to automatically read the test pattern, thereby obtaining an optimum amount of correction.